Air Pollution Causes Dementia

Why in News?

Recently, Cambridge University researchers have found that long-term exposure to air pollution is linked to an increased risk of developing dementia.

What is Dementia?

• Dementia – It is a term for several diseases that affect memory, thinking and the ability to perform daily activities.
• Vulnerable – It mainly affects older people.
• Symptoms – Forgetting recent events and having difficult to recalling familiar persons, names.
• Conversation – Difficult to communicate with others.
• Decision making – Struggling to make quick decision.
• Spread – Around 57 million people had dementia worldwide in 2021, with the number expected to increase to at least 150 million by 2050.
• Vulnerable – It mainly affects older people.
• Symptoms – Forgetting recent events and having difficult to recalling familiar persons, names.
  • Conversation – Difficult to communicate with others.
  • Decision making – Struggling to make quick decision.
• Spread – Around 57 million people had dementia worldwide in 2021, with the number expected to increase to at least 150 million by 2050.

Which air pollutants are related to dementia?

• Air pollutants – They are substances present in the air at higher-than-normal levels that may harm living organisms, materials, or the environment.
• They can take the form of solid particles, liquid droplets or gases, and come from both natural and human-made sources.

• PM2.5 (Fine Particulate Matter) – PM2.5 is extremely fine particulate matter with a diameter of 2.5 micrometers or less.
• They are predominantly produced by vehicle emissions and thermal power plants.
  • Risks - Each 10 µg/m³ increase in long-term exposure to PM2.5 may raise the risk of dementia by 17%.
• Nitrogen dioxide (NO2) - Produced primarily due to the burning of fossil fuels by vehicles, thermal power plants, and various industrial processes.
  • Risks - For Every 10 μg/m³ of long-term exposure to nitrogen dioxide, the relative risk of dementia increased by 3%.
• Soot or Black Carbon – Origin from vehicle exhaust emissions and burning wood.
  • Risks - 13% increase in dementia risk per 1 µg/m³ of long-term exposure

How air pollutants increase risks of dementia?

• Neural damage – It causes inflammation in the brain which leads to neural damage.
• Oxidative stress – It results in an imbalance between reactive oxygen species (ROS) and the body’s defence systems.
• Cell damage – Excessive ROS can harm brain cells, contributing to the development of neurodegenerative conditions like dementia.
• Direct Brain damage – Air pollutants may directly enter the brain, bypass protective barriers and initiating harmful processes.
• Indirect effects – Air pollution can also affect brain health through systemic inflammation and pathways shared with heart and lung diseases.

What lies ahead?

• Individual actions and policy changes may reduce exposure to air pollutants.
• An interdisciplinary approach can support better prevention of dementia.
• Urban planning, transport policy, and environmental regulation can play a key role in promoting public health and preventing dementia.

Reference

The Indian Express | Risk of Dementia